add ons.
You dont have to buy any of them. You get a VRC/generic brand of everything with subscription. For Spec class, the chassis of all brands are free. If you want you can purchase more chassis, motors, esc's etc etc with either real money, or VRC Euros which you earn just for participating in weekly and monthly official timed events ( which are also free ) The Euros add up fairly quick especially if you do well and enter several events per week. I earn about $4-5 per week just running weekly events and getting in top 40-60, Generally I buy a new track every so often if a new one comes out.
As a practice tool I like it. You have to do set ups for each car and track, and its pretty stinking detailed on the adjustments you can make. Maybe not exactly real life, but close enough. Plus when I cant get to the track ( which is about once every 2 weeks) VRC soothes the urge. the 1/12 scale is my favorite right now, mod and 10.5. Lots of TC racing both electric and Nitro plus 1/8 scale too if that's your thing.